Lock Button is stuck

Is there an easy way to pop off the back of the phone and see what's going on with the lock button? It sticks and I have to push down with force for the phone to lock. I'd like to trade my phone in for a new one and know I will be low balled for reimbursement if I go in with it stuck.

Lock Button is stuck

Thanks, I'll take it into Apple. I've had the phone for over 2 years. Thinking of switching to Samsung but I'll lose my unlimited data if I do that. So it's either fix my iPhone and stick with V or try to find a better deal.